This battery is provided with a power generating element, a battery case main body, a battery case lid, an electrode terminal member which is connected electrically to the power generating element inside of the battery case body and which extends outside of the battery case lid, and an outer insulation member which is arranged on the battery case lid and insulates the electrode terminal member from the battery case lid. The battery case lid is fitted inside of the opening and welded to the battery case main body by irradiating a laser from above the battery case lid towards the boundary section between the battery case lid and the battery case main body. Furthermore, this battery is provided with a plume control portion which prevents the plume that rises from the boundary portion during welding from rising towards the outer insulating member.